1. Field of the Invention
The present invention relates to a moving body detection system for detecting moving bodies by exchanging signals between moving bodies such as vehicles and pedestrians, etc.
2. Description of the Background Art
Various methods have been put forward in the related art for detecting other approaching vehicles and other moving bodies while driving.
For example, in Japanese Patent Laid-open Publication No. Hei 2 (1990)-216600, a receiving device provided in a vehicle carries out monitoring as the vehicle progresses. An alarm is generated and the presence of a moving body is made known as a result of the receiving device receiving an alarm signal transmitted by a transmission device provided on another moving body.
However, as the number of moving bodies that cause the alarm is not known, when only one vehicle is confirmed by sight it is difficult to be aware of the presence of other vehicles.
Therefore, as disclosed in Japanese Patent Laid-open Publication No. Hei 7(1995)-225274, confirmation is displayed as a result of discerning whether or not one or a plurality of moving bodies exist within a prescribed distance by comparing intervals in the increases of consecutive pulses occurring in a receive signal with a reference period.
However, only whether one or a plurality of opposing moving bodies is present is known and it is not possible to be aware of configurations such as an arrangement when a plurality of moving bodies are present.
Namely, for example, when a plurality of groups configured of a number of cars in close proximity are travelling, it cannot be discerned whether there is one large group or a number of small groups.
It is therefore important for the driver of the vehicle to understand not just information that one or a plurality of moving bodies exist but also to understand how such moving bodies are arranged.
Further, when there is a multiplicity of opposing moving bodies, transmitted signals become mixed up and it is not possible to receive signals in a reliable manner due to mixed lines etc.
As it is the object of the present invention to resolve the aforementioned problems, the present invention sets out to provide a moving body detection system capable of receiving response signals in a reliable manner and discerning the configuration of the arrangement of opposing moving bodies.
In order to achieve the aforementioned object, in, the present invention there is provided a moving body detection system for transmitting and receiving signals in such a manner that moving bodies can detect each other. Each moving body transmits an ID code for identifying the moving body itself and giving a priority to the moving body as an ID code signal of a fixed time period. Each moving body receives the ID code signals of other moving bodies. Each moving body receiving an ID code signal makes a determination as to whether or not a neighboring upper order moving body of a higher order than itself is present within a prescribed distance. Each moving body determining the presence of a neighboring upper order moving body receives a detection signal transmitted from a detection side moving body and transmits a response signal only when the neighboring upper order moving body is determined not to be present.
As a response signal is then transmitted with respect to a detection signal only when it is discerned that there is no neighboring upper order moving body of an ID code of a higher order priority than a moving body itself within a prescribed distance of the moving body itself, the moving body of the highest order ID code within a group of moving bodies within a prescribed distance transmits a response signal representative of the group.
As a moving body representative of each group transmits a response signal, the detection side moving body receiving this signal can be aware of the main parts of the configuration of the opposing moving bodies that are deemed necessary.
Only a moving body typical of the group transmits a response signal and other moving bodies do not transmit response signals. The response signals therefore do not become mixed up and can be received in a reliable manner.
In a second aspect of this invention, there is provided a moving body detection system for transmitting and receiving signals in such a manner that moving bodies can detect each other, wherein each moving body can identify a type to which it itself belongs and transmits an ID code for identifying itself and giving itself a priority with respect to each type as an ID code of a fixed period, each moving body receives ID code signals from other moving bodies, a moving body receiving an ID code makes a determination as to whether or not a neighboring upper order moving body belonging to the same type, and of an ID code of a higher order priority than itself is present or not within a prescribed distance. A moving body determining the presence of a same type of neighboring upper order moving body transmits a response signal only when a same type neighboring upper order moving body is determined not to be present when a detection signal transmitted from a detection side moving body is received.
A response signal is transmitted with respect to a detection signal only when it is determined that a same type neighboring upper order moving body of an ID code of a higher order priority than the moving body and belonging to the same type does not exist within a prescribed distance. A response signal typical of the same type of moving body is therefore transmitted by the moving body of the highest order ID code for each type within a group of moving bodies within a prescribed distance.
Moving bodies are classified into large vehicles, small vehicles, motorcycles, bicycles and pedestrians etc., and when each type of moving body is present as a moving body constituting a group, a response signal is generated by a moving body that is representative of each group. The receiving side moving body that then receives this signal can then be aware of the configuration of the group of opposing moving bodies and the main aspects of the configuration of moving bodies within a group.
As just a moving body representative of the moving bodies of the same type transmits a response signal and other moving bodies do not, the response signals do not become mixed up and can be reliably received.
In a third aspect of this invention, there is provided a moving body detection system for transmitting and receiving signals in such a manner that moving bodies can detect each other, wherein a second moving body receiving a detection signal transmitted by a first moving body transmits a response signal with respect to the detection signal except in the case where a response signal transmitted previously by a third moving body within a prescribed distance from the second moving body is received by the second moving body.
The second moving body transmits a response signal with respect to the detection signal except when a response signal has been received previously from a third moving body within a prescribed distance. Other moving bodies therefore do not transmit a response signal with respect to the detection signal when a response signal is received previously from within a group of moving bodies within a prescribed distance.
Namely, a moving body that has transmitted a response signal previously with respect to a detection signal generates a response signal as a moving body that is representative of each group. The main aspects of the configuration of the opposing moving bodies can therefore be known at the first moving body on the detection side that receives the response signal.
The response signals can therefore be received in a reliable manner without becoming mixed up because a response signal is only transmitted by a moving body that is representative of a group and not by other moving bodies.
In a fourth aspect of this invention, a type code identifying the type of a moving body is included in the response signal, and the second moving body transmits a response signal with respect to the detection signal with the exception of the case where a response signal from the second moving body has already been received from the third moving body belonging to the same type as the second moving body.
The second moving body generates a response signal with respect to the detection signal except when a response signal transmitted by the third moving body within a prescribed distance and belonging to the same type is received previously. Other moving bodies of the same type therefore do not transmit response signals with respect to the detection signal when a response signal is transmitted beforehand from a moving body of the same type within a group of moving bodies with the prescribed distance.
When each type of moving body exists as moving bodies constituting a group, a response signal is generated by a representative moving body that has generated a response signal beforehand for each type. The configuration of a group of opposing moving bodies and the configuration of the main parts of moving bodies within a group can therefore be known at the first moving body on the detection side that receives this response signal.
As just a moving body representative of the moving bodies of the same type transmits a response signal and other moving bodies do not, the response signals do not become mixed up and can be reliably received.
In a fifth aspect of this invention, a moving body receiving the detection signal measures the distance to the moving body transmitting the response signal based on the received response signal.
The main aspects of the arrangement of the non-detection side moving bodies can be known at the detection side moving body by measuring the distance to the moving body that generated the response signal.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.